when the big rocket flies, what are those "white stuff" falling down?

If it's liquid fueled, I'd guess ice...

If it's the solid fuels (i.e. MX), I'd guess tiles...

I tried to guess which big rocket but couldn't get the answer...

the fuel is supposed inside the tube. why there is ice?

the moon rocket, any big rocket.

Condensation from the atmosphere. Its the same reason that a glass of ice water gets wet on the outside. Since liquid oxygen is at -183.0°C and liquid hydrogen is at -252.8°C the container (ie, the rocket body) gets really cold, and the air next to the container gets cold also. At cold temperatures the air can't hold as much water vapor, so the vapor in the air condenses out onto the rocket. However, since the rocket is well below the freezing point of water (0°C) the vapor turns to ice.

Then, when the rocket launches, vibration, expansion and contraction, and air flow all combine to break the ice from the surface.

Mark E. "No, I'm not exactly a rocket scientist" Hamilton NAR #48641-SR ARSA #418

Because the fuel has to be very cold to be liquid.

(hmm, me answer like question is)

big rocket cold

Mongo

While the other answers may have an element of truth I much prefer the answer given a while ago here on rmr by Tod Hilty...

From google :

Do not believe the previous posts, as they're all wrong.

What you see falling off is actually excess "sugar glazing" similar to the type used on Glazed Doughnuts.

Based on intelligence collected by thousands of sport rocketeers nationwide, NASA determined that the Rocket Gods intensely hate rockets that taste like Glazed Doughnuts. In a paramount security decision, the entire Saturn V was coated with a sugar glaze in order to prevent the Rocket Gods from eating it as it ascended through the atmosphere...

And, by golly, it worked!

Tod "Ice, really.." Hilty

Cheers Mike 8-{>

-- UKRA #1208 L1 EARS # 1118 TRA #3207 L1

-=*=- Gravity is a harsh Mistress -=*=-

-=*=- The Tick -=*=- Remove .co.uk from Reply To: address.

Mmmm. Glazed rockets.....

Zooty

Moisture droplets form on the outside of liquid-fuelled rockets the same way they do on your your iced tea glass. The difference is that liquid-fueled rockets are very, very cold so the condensation turns to a layer of ice that coats the outside of the rocket. At launch time the ice flakes off and falls away from the rocket.

I like the sugar glaze theory, myself. Before January's launch, I'm gonna take my fleet to Krispy Kreme and pass them through the "wall of glaze".

-- Eric Benner TRA # 8975 L2 NAR # 79398

I like the glaze theroy to, but I think I'll just buy the doughnuts. Cardboard sticks betweem my teeth.

Mark E. hamilton

Ya know. I just thought of something.

Based on the VB "Spudnick" kit.....

replace the styrofoam ball with a popcorn ball replace the stabilization sticks with Pixie sticks "paint" with cake icing or melted chocolate fly it on a sugar motor at an EX launch

It would be almost completely edible.

-- Eric Benner TRA # 8975 L2 NAR # 79398

LOL! I love it!